Abstract: An adjustable fuel delivery regulation assembly is provided which can be disposed within a direct oxidation fuel cell system, or the fuel reservoir or fuel tank that supplies such a system. One embodiment of the fuel delivery regulation assembly is a shutter assembly, which includes two correspondingly perforated components. The two components can be positioned relative to one another such that the apertures in each component are aligned in certain ways. In an open position, the apertures are substantially fully aligned to permit full fuel flow. In a closed position, the apertures are offset such that there is no opening; thereby fuel flow is restricted. Intermediate positions allow adjustments in the amount of fuel flow proportional to the size of the openings. In accordance with another embodiment of the invention, a set of rotatably mounted slotted rods is inserted into a housing through which fuel can flow through openings in the housing.

Abstract: An adjustable fuel delivery regulation assembly is provided which can be disposed within a direct oxidation fuel cell system, or the fuel reservoir or fuel tank that supplies such a system. One embodiment of the fuel delivery regulation assembly is a shutter assembly, which includes two correspondingly perforated components. The two components can be positioned relative to one another such that the apertures in each component are aligned in certain ways. In an open position, the apertures are substantially fully aligned to permit full fuel flow. In a closed position, the apertures are offset such that there is no opening; thereby fuel flow is restricted. Intermediate positions allow adjustments in the amount of fuel flow proportional to the size of the openings. In accordance with another embodiment of the invention, a set of rotatably mounted slotted rods is inserted into a housing through which fuel can flow through openings in the housing.

Abstract: The present invention includes an open-loop AMTEC cell operable in a delivery mode and in a priming mode. In the delivery mode, the cell provides electrical potential through electrochemical reactions, which persist until the ion content of the cell is exhausted. In the priming mode, the electrochemical potential of the cell is established through an outside electrical potential or through a reversal of the thermal gradient within the cell. The cell of the present invention is particularly operable in accordance with a preferred method and also as a component of a suitable electrical system.

Abstract: An alkali metal thermal to electric converter (AMTEC) cell of the type employing an alkali metal flowing between a hot end of the AMTEC cell and a cold end of AMTEC cell. The AMTEC cell being separated into a low-pressure zone and a high-pressure zone and comprising a condenser communicating with the low-pressure zone for condensing alkali metal vapor migrating through the low-pressure zone from the solid electrolyte structure, a return channel coupled to the condenser for directing the condensed alkali metal from the condenser toward the hot end of the AMTEC cell, an evaporator coupled to the return channel and communicating with the high-pressure zone for evaporating the condensed alkali metal into the high-pressure zone, the evaporator including an evaporation surface, and a solid electrolyte structure separating the low-pressure zone and the high pressure zone and having alkali metal simultaneously existing in a vapor and liquid state in its interior.

Abstract: The present invention provides an ionic and electronic insulator interposed between a BASE tube and a tube mounting member in an AMTEC cell for preventing shunt currents from forming between BASE tube electrodes. In a first embodiment of the invention, an insulator is formed integral with the BASE tube by leaching out an alkali metal ion component of the BASE tube at a desired location. In a second embodiment of the present invention, an alpha alumina ring is brazed to the end of the BASE tube. In a third embodiment of the present invention, a glass material seal is formed between the BASE tube and the mounting member.

Abstract: The present invention provides an alkali metal thermal to electric conversion (AMTEC) cell of the type employing an alkali metal flowing between a high-pressure zone and low-pressure zone in the cell through a solid electrolyte structure. The cell preferably includes a condenser communicating with the low-pressure zone for condensing alkali metal vapor migrating through the low-pressure zone from the solid electrolyte structure. An artery is coupled to the condenser for directing condensed alkali metal from the condenser toward a hot end of the cell. An evaporator for evaporating the condensed alkali metal is coupled to the artery channel and communicates with the high-pressure zone. The artery and evaporator combine to form a return channel which preferably includes a graded pore size capillary structure for creating a region having a large pore size transitioning in any predetermined manner to a region having a relatively smaller pore size.

Abstract: The present invention provides an alkali metal thermal to electric conversion cell having radially projecting beta-alumina type solid electrolyte elements and a central heat input region.

Abstract: The present invention provides an alkali metal thermal to electric conversion (AMTEC) cell of the type employing an alkali metal flowing between a high-pressure zone and low-pressure zone in the cell through a solid electrolyte structure. According to the invention, the cell preferably includes a condenser communicating with the low-pressure zone for condensing alkali metal vapor migrating through the low-pressure zone from the solid electrolyte structure. A return channel is coupled to the condenser for directing condensed alkali metal from the condenser toward a hot end of the cell. An evaporator is coupled to the return channel for evaporating the condensed alkali metal and communicates with the high-pressure zone. The evaporator includes means for controlling an evaporation front position of the alkali metal in response to variations in the temperature gradient within the cell as caused by load changes on the cell.

Abstract: The present invention provides an AMTEC cell having a more robust power conductance path (conduction, radiation, convection, and latent heat transfer) from the heat input surface of the cell to the working fluid, evaporation surface, and SES. More particularly, one embodiment of the present invention includes collars, post and/or bridges extending between the SES support plate and the heat input surface. In another embodiment, a plurality of channels or conduits extend between the heat input surface and SES support plate. These embodiments simultaneously increase the thermal conductance path between the heat input surface of the cell and the evaporation surface as well as between the heat input surface of the cell and the SES, and enables superheating of the working fluid.

Abstract: The present invention provides an alkali metal thermal to electric conversion (AMTEC) cell of the type employing an alkali metal flowing between a high-pressure zone and low-pressure zone in the cell through a solid electrolyte structure. The cell preferably includes a condenser communicating with the low-pressure zone for condensing alkali metal vapor migrating through the low-pressure zone from the solid electrolyte structure. An artery is coupled to the condenser for directing condensed alkali metal from the condenser toward a hot end of the cell. An evaporator for evaporating the condensed alkali metal is coupled to the artery and communicates with the high-pressure zone. A heat shield is disposed in the low pressure zone of the cell for reducing the radiative heat transfer between the hot end of the cell and the cold end of the cell. The heat shield preferably includes a first end having a known area transitioning to a second end encompassing a smaller area than the first end.

Abstract: A high voltage multitube alkali metal thermal electric convertor having a plurality of closely packed tubular cells disposed in a tube sheet in a vessel and electrically connected in series, the tube sheet dividing the vessel into a high pressure high temperature portion having a wick and heater disposed therein and a low pressure low temperature portion having a wick disposed in a condenser from which heat is removed; a pump for transferring liquid metal therebetween and a tab on a wick disposed in the tubular cell to remove excess liquid metal and prevent shorting between the cells.

Abstract: A flat plate alkali metal thermoelectric converter module having a plurality of generally flat plate cells grouped in stacks that are electrically connected in series within the stack, the cells being disposed to minimize the heat energy radiated to a condenser to provide a high efficiency module.

Abstract: An alkali metal thermoelectric conversion device formed from a porous tube or plate coated with a thin film of beta-alumina, the porous tube or plate is sintered metal or metal alloy having a coefficient of thermal expansion which approaches that of the beta-alumina to form a mechanically stable device with high electrical output.

Abstract: The present invention pertains to a stacked AMTEC module. The invention includes a tubular member which has an interior. The member is comprised of a ion conductor that substantially conducts ions relative to electrons, preferably a beta"-alumina solid electrolyte, positioned about the interior. A porous electrode for conducting electrons and allowing sodium ions to pass therethrough, and wherein electrons and sodium ions recombine to form sodium is positioned about the beta"-alumina solid electrolyte. The electrode is operated at a temperature and a pressure that allows the recombined sodium to vaporize. Additionally, an outer current collector grid for distributing electrons throughout the porous electrode is positioned about and contacts the porous electrode. Also included in the invention is transporting means for transporting liquid sodium to the beta"-alumina solid electrolyte of the tubular member. A transition piece is positioned about the interior of the member and contacts the transporting means.

Abstract: A self-actuated shutdown system incorporated into a reactivity control assembly in a nuclear reactor includes pumping means for creating an auxiliary downward flow of a portion of the heated coolant exiting from the fuel assemblies disposed adjacent to the control assembly. The shutdown system includes a hollow tubular member which extends through the outlet of the control assembly top nozzle so as to define an outer annular flow channel through the top nozzle outlet separate from an inner flow channel for primary coolant flow through the control assembly. Also, a latching mechanism is disposed in an inner duct of the control assembly and is operable for holding absorber bundles in a raised position in the control assembly and for releasing them to drop them into the core of the reactor for shutdown purposes.